Whats wrong with my Stag OLL??? *UPDATE 5/21*

[RobG]

Scenario: brand new Stag upper/lower, 10 round Bushys, American Eagle 55 gr fmj. First mag, one jam; round 5 jammed between mag and chamber but was easily cleared and was fine for rest of mag. Next mag had 3 failures to pick up a round. From then on, one to two rounds would fire but another round wouldn't be picked up. Then worsened to; would only fire a single round and never pick up another. It would pick up if I manually pulled the charging handle. I have two mags and they did the same thing. Tried different boxes, though same brand, but same thing

Definitely need some help. This is my first OLL so I am "green" to say the least.

What a let down

[Prc329]

I had a similar problem with AE. It would not properly cycle the bolt. XM193 would work fine.

[Draven]

Breakin period?

[JOEKILLA]

Magazines

[bwiese]

First, Do you have a Stag 16" or 20" upper?

The 20" Stags have non-chrome-lined barrels - there's always the chance of tight/rough chamber, though I expect Stag to stand head & shoulders above other lowball vendors (Oly, etc.) in this aspect.l

Lube issues are the #1 problem for AR malfunctions after substracting out crap magazines and crap ammo (neither of which you appear to have).

Have you lubricated your rifle according to the USGI tech manual (you can find it on AR15.COM or Maryland AR15 Shooter's Site).

Does it pass the basic function test in the manual? (empty rifle!)

Your bolt, bolt carrier, bolt lugs and mating rceiver extension lugs should all be lubed with CLP - almost 'wet'. So should inside of upper receiver, and charging handle.

The bolt itself should be well-lubed around the extractor & ejector areas. Exercise the extractor & ejector with a tool to ensure they actually move and are not stuck.

Check that your buffer/spring assy in the stock moves freely & smoothly along its full path without any restriction/binding.

Are you running a fixed mag rifle or a featureless rifle with detachable magazines? Sometimes fixed mags may have slight issues esp if the mag catch hole is cut a tad off -likely again not a prob w/Bushy mags.

Just in case, exercise the followers in your magazines several dozen times with a popsicle stick, ruler, etc.

Ensure your bolt carrier gas key is staked on and not loose. (Unlikely with Stag.)

Wrong spring/buffer in assembly (mixing CAR vs A2 hardware) can cause problems. Misassembled lower receiver parts (disconnctor spring exchanged for bolt catch spring) can show weird problems too.

[bwiese]

Breakin period?

No such thing/ not really an issue on a quality AR, like a Stag.

Any properly lubricated AR should run 100% out of the box w/standard ammo and a quality mag.

I've built a ton of ARs and they all work out of the box - even with Wolf ammo.

[bwiese]

I had a similar problem with AE. It would not properly cycle the bolt. XM193 would work fine.

That's not AE's fault. While it has less oomph than XM193, it is a sign that something is wrong with the rifle - poor lube, gas system leaky or blocked, loose/unstaked gas key, wrong buffer/spring for carbine vs. rifle, etc.

Every one of my (and many others') ARs runs fine with Fed AE.

[Draven]

No such thing/ not really an issue on a quality AR, like a Stag.

Any properly lubricated AR should run 100% out of the box w/standard ammo and a quality mag.

I've built a ton of ARs and they all work out of the box - even with Wolf ammo.

My AR hated the wolf we tried in it the other weekend. Maybe there's crud in my gas port- i need some pipe cleaners errrr 'gas port cleaning tools'

[bwiese]

My AR hated the wolf we tried in it the other weekend. Maybe there's crud in my gas port- i need some pipe cleaners errrr 'gas port cleaning tools'

NO NO NO NO NO NO.

There is not. It blows out.

Do not clean the gas tube, etc. with pipe cleaners. You will make things worse and redistribute gunk and possibly leave cotton debris that chars and futher builds up.

If your AR does not run Wolf, something is wrong. Poor lube is #1 issue aside from non-chrome-lined barrel/tight/rough chamber.

Who makes your gun/upper?

Please go to AR15.COM or Maryland AR15 shooters site and read up on the USGI manuals for proper cleaning and debugging.

[PistolPete75]

i bought a stag upper recently. had the same issues. 1. get rid of those bushmasters, and go buy stag 10 rounders. 2. do a complete field strip and clp, clp, clp, clp, the hell out of it. did i say clp? 3. change the blue extractor for a black one (dpms midwayusa), 4. install crane o ring, 5. check to make sure that there are no fitment issues. 5. shoot away.

if that doesn't work, install new buffer spring.

[Prc329]

That's not AE's fault. While it has less oomph than XM193, it is a sign that something is wrong with the rifle - poor lube, gas system leaky or blocked, loose/unstaked gas key, wrong buffer/spring for carbine vs. rifle, etc.

Every one of my (and many others') ARs runs fine with Fed AE.

Hmmmm. I'll try lubing it a bit better and your suggestions above. I thought I lubed it properly. It was very strange. It only happened with AE and steel case wolf. Everything else I ran threw it, winchester, fiocchi and xm193 all cycled fine.

[Ronco]

My guess is "wrong buffer/spring for carbine vs. rifle" (as Bill said)

This happened to a friend of mine back in the 90's. He changed the spring to the right size and never had another prob.

[bwiese]

Off-brand (i.e, bottom feeders like Oly, Model1 Sales, etc.) rifles are very prone to having poor quality springs with widely varying spring tensions from gun to gun.

Also, use of "H" or "H2" heavy buffers may cause problems for non-XM193/non-M855 milspec ammo.

[Fjold]

First, Do you have a Stag 16" or 20" upper?

The 20" Stags have non-chrome-lined barrels - there's always the chance of tight/rough chamber, though I expect Stag to stand head & shoulders above other lowball vendors (Oly, etc.) in this aspect.l

There is more chance with a tight chamber with the chrome lined chamber.

The chambers are cut with the same reamers and the chrome lining is added after the cutting and boring is done.

Chrome plating is strictly for erosion/corrosion resistance and has a negative effect on accuracy.

[bwiese]

There is more chance with a tight chamber with the chrome lined chamber.

The chambers are cut with the same reamers and the chrome lining is added after the cutting and boring is done.

Nope - I disagree, kinda for opposite of the reasons you cite.

For ARs, chrome-lined bbls are designed to have milspec chamber dimension and thus are a little looser. (It would be refreshing to see a Wylde-chambered chrome-lined bbl.)

Many non-chrome-lined bbls in the AR world are sold as "match" chambers that are much tighter and/or are for 223 and not 5.56 w/NATO pressures Bottom feeder vendors sometimes leave these rough.

Even with equal tightness, the chrome-lined chamber will offer higher lubricity.

Chrome plating is strictly for erosion/corrosion resistance and has a negative effect on accuracy.

The latter part is not necessarily true. It's a side issue. This is more a function of rejection criteria after plating and lack of finish reamer ability. Some subset of chrome-lined production will be 'on the nose'. The vendor chooses to sell the other bbls too.

Some vendors reject more, some accept more. It appears CMMG bbls do very very well, and are capable of subMOA. Their bbl prices are a tad more, too I think this reflects this.

Have you ever shot an FN SPR 308 bolt gun w/Fed GMM ammo? That's a same-hole gun that duplicates or exceeds most 308 varmint guns and Rem 700 PSSes or 700 LTRs. It can be done, and the myth about chrome lining is spread by small rifle shops that can't afford to do a batch of chrome-lined barrels.